Incontinence is an affliction that prevents a patient from controlling waste elimination functions. As one might expect, this condition can be quite debilitating and embarrassing and may severely limit the patient's activities.
Various techniques exist for treating incontinence in patients. One such technique is surgical implantation of an artificial sphincter. One form of artificial sphincter includes an appropriately sized inflatable cuff that is positioned around a duct such as either the urethra or the rectum, depending upon the nature of the incontinence. A control pump is fluidly coupled to the cuff and to a pressure-regulating balloon, both of which are positioned within the body of the patient. Under normal conditions, the cuff is inflated which causes a compression of the urethra or the rectum, thus preventing unintentional discharge. When so desired, the patient manually actuates the control pump. Fluid is then withdrawn from the cuff and forced into the pressure-regulating balloon. As this occurs, the cuff relaxes, allowing the urethra or rectum to expand and open. At this point, normal waste elimination functions are permitted. The pressure-regulating balloon contains a volume of fluid that is maintained at a relatively high pressure. The control pump is provided with a fluid resistor that allows pressurized fluid from the balloon to slowly return to the cuff causing it to automatically re-inflate.
One such artificial sphincter or inflatable cuff employs a generally rectangular inflatable member that is wrapped about the outer circumference of the duct and the ends are connected together. As pressure is increased and the cuff inflates, the interior area defined by the cuff is compressed, thus achieving the desired results. The cuff may be formed from silicone, which has proven to be a reliable and medically safe material that is usually compatible with human tissue.
Due to the nature and configuration of the rectangular chamber that forms the cuff, a non-continuous geometrical configuration is produced. That is, the wall of the cuff which forms the interior circumference, (i.e., that which is in contact with the duct), has one or more fold lines that develop. In some instances, the fold lines form in a triangular configuration so as to apply pressure to multiple sides of the urethra or rectum. At smaller sizes, the chamber may be prevented from forming a triangular configuration when wrapping around the urethra or rectum. Instead, the chamber can be disposed to create a single fold line proximate a center of the chamber. This configuration can lead to undesired discharge through the duct as well as abrasion, wear and fatigue of the duct and/or inflatable chamber.